1. Field of the Invention
The present invention relates generally to a recording and/or reproducing apparatus for a flexible rotary recording medium, such as a flexible magnetic disk. More specifically, the invention relates to an apparatus for stabilizing a recording medium for a writing and/or reading head of the recording and reproducing apparatus. Further particularly, the invention relates to a disk stabilizing apparatus for the recording and/or reproducing apparatus which is suitable for use in an electronic still camera, for example.
2. Description of the Background Art
In the recently developed and marketed electronic still cameras, one field of video data representative of a still image is magnetically recorded on a flexible magnetic disk in a form of a frequency modulated signal. The recording format of the video data signal is of short wavelength. In order to stably transfer data between a magnetic head and the disk, the magnetic head is installed on a stabilizer plate for drawing the disk toward the head by vacuum pressure generated while the disk is driven to rotate.
FIGS. 7, 8, 9 and 10 show conventional constructions of a disk stabilizing mechanism for the recording and/or reproducing apparatus for the flexible magnetic disk. In order to facilitate a better understanding of the invention, the construction of the conventional disk stabilizing mechanism will be briefly discussed with reference to FIGS. 8, 9 and 10. A thin flexible sheet form magnetic disk A is mounted on a stabilizer plate or pad 1 which is formed into a disc shaped configuration. The stabilizer plate 1 is formed with a stabilizer surface 1a toward which the magnetic disk A is to be drawn. An essentially rectangular recess or bore 1b is formed at the center portion of the disc shaped stabilizer plate. A magnetic head 2 is disposed within the recess or bore 1b. The magnetic head 2 is arranged in the recess 1b so that the tip end thereof may project in a magnitude of several tens .mu.m's from the stabilizer surface 1a.
As shown in FIG. 8, the stabilizer plate 1 is designed to be caused shifting together with the magnetic head 2 in the radial direction P by means of a head shifting mechanism 3. Therefore, the magnetic head 2 is shifted to access coaxially or helically arranged recording tracks across the disk. In order to cause radial shifting of the stabilizer plate 1, a head carriage 4 is provided. The head carriage 4 is movably guided by a pair of slide shafts 8a and 8b mounted on an upper chassis 5a and carries the stabilizer plate 1 with the magnetic head 2 in a radial direction. The head carriage 4 is drivingly associated with a tracking motor 9 via a smaller diameter gear 9a and a larger diameter gear 10. The larger diameter gear 10 has a cam plate 10a which is engaged with a cam follower 4a extending from the head carriage 4. The larger diameter gear 10 is engaged with the smaller diameter gear 9a for rotatingly driving the cam plate 10a. By rotation of the cam plate 10a, the cam follower 4a is driven to cause radial shifting of the carriage 4 in a radial direction to determine the position of the magnetic head 2 according to the angular position of the cam plate 10a. Therefore, the stabilizer plate 1 with the magnetic head 2 is shifted toward and away from the rotary shaft of a turn table 7.
While the disk A is driven to rotate by rotation of the turn table 7, a Berboulli drawing force is generated between the disk A and the stabilizer plate 1 for establishing steady contact between the disk and the head. Such technology for stabilizing contact between the magnetic head and the flexible magnetic disk has been disclosed in Curtis R. Regruit U.S. Pat. No. 4,600,955 and Robert G. Hills U.S. Pat. No. 4,620,250, for example.
In such arrangement, if upward curving is caused in the magnetic disk at a radially outward portion as illustrated in FIG. 9, the head receptacle recess is exposed to the atmosphere to cause failure in establishing contact between the magnetic head and the magnetic disk. In order to eliminate a possibility of causing failure in establishing a steady contact between the magnetic head 2 and the magnetic disk A the stabilizer plate 1 is inclined in a radially outward direction R, as shown in FIG. 7. The inclination angle .theta. is selected in a range of 1.degree. to 2.degree. for placing the stabilizer surface 1a in a position substantially parallel to the disk surface deflected upwardly. Though this strategy may provide certain improvement in eliminating a possibility of failure in contacting the head 2 onto the disk A, it is still not possible to completely prevent failure of contact between the magnetic head and the magnetic disk due to variation of magnitude and/or angle of curving caused in the disk.